This conference will bring together basic scientists and clinician scientists from a variety of disciplines whose research deals with some aspect of the interaction of calcium with oxalate to form crystals. Such scientists will include plant biologists who investigate the orderly formation of calcium oxalate crystals of precise shape in specialized plant cells, microbiologists who examine the ability of microorganisms to metabolize oxalate, nutritionists who study the absorption and bioavailability of dietary calcium and oxalate, physiologists who examine the transport of calcium and oxalate and their interaction with organs, biochemists and cell biologists who investigate aspects of intracellular function and metabolism, and clinical scientists who examine the pathophysiology of calcium oxalate crystallization, particularly in the formation of kidney stones. The goals of the Conference are (i) to identify issues of consensus and controversy; (ii) to promote a cross-fertilization of ideas; (iii) to provide opportunities that facilitate scientific collaborations; and (iv) to promote scientific exchange of information, ideas and methodologies. Nine scientific sessions will be held on the following topics: 1) Calcium oxalate in plants and microbes; 2) Nutritional aspects of calcium oxalate ingestion; 3) Absorption and secretion of calcium and oxalate; 4) Oxalate synthesis and its functional role; 5) Model systems; 6) Renal handling of calcium and crystallization inhibitors; 7) Renal pathophysiology in stone formation; 8) Calcium oxalate crystallization; 9) Mechanisms of calcium oxalate stone formation. The Speakers and Session Chairs consist of internationally recognized leaders in their fields and include 30 from the U.S., 11 from Europe, 2 from Asia, 1 from Australia and 1 from South Africa. An intentional effort has been made to include females, minorities and young investigators among the Speakers and Session Chairs and their attendance at the Conference will be encouraged. Funds requested in this proposal are to partially offset registration fees and travel expenses of the Speakers and Session Chairs and to provide a similar level of support to enable 25 additional new, minority or disabled investigators to attend the Conference. The balance of the funding will be obtained from Pharmaceutical and Biotechnology Companies and organizations with an interest in sponsoring this topic. It is anticipated that this Conference will have a significant impact in promoting research in several health related fields including kidney stones and primary hyperoxaluria.